AWR report interpretation

Link: http://www.remote-dba.net/oracle_10g_tuning/t_reading_awr_report_sections.htm

The main sections in an AWR report include:

Report Summary

Load Profile

Top 5 Timed Events

Wait Events Statistics Section

Wait Events

Background Wait Events

Operating System Statistics

Time Model Statistics

Service Statistics

SQL Section: This section displays top SQL, ordered by important SQL execution metrics.          SQL Ordered by Elapsed Time: Includes SQL statements that took significant execution time during processing.

          SQL Ordered by CPU Time: Includes SQL statements that consumed significant CPU time during its processing.

          SQL Ordered by Gets: These SQLs performed a high number of logical reads while retrieving data.

          SQL Ordered by Reads: These SQLs performed a high number of physical disk reads while retrieving data.

          SQL Ordered by Parse Calls: These SQLs experienced a high number of reparsing operations.

          SQL Ordered by Sharable Memory: Includes SQL statements cursors which consumed a large amount of SGA shared pool memory.

          SQL Ordered by Version Count: These SQLs have a large number of versions in shared pool for some reason.

I/O Section: This section shows the all important I/O activity for the instance and shows I/O activity by tablespace, data file, and includes buffer pool statistics.          Tablespace IO Stats 

          File IO Stats 

          Buffer Pool Statistics 

Advisory Section: This section show details of the advisories for the buffer, shared pool, PGA and Java pool.          Buffer Pool Advisory 

          PGA Aggr Summary: PGA Aggr Target Stats; PGA Aggr Target Histogram; and PGA Memory Advisory. 

          Shared Pool Advisory 

          Java Pool Advisory 

Segment Section: This report section provides details about hot segments using the following criteria:          Segments by Logical Reads: Includes top segments which experienced high number of logical reads.

          Segments by Physical Reads: Includes top segments which experienced high number of disk physical reads.

          Segments by Buffer Busy Waits: These segments have the largest number of buffer waits caused by their data blocks.

          Segments by Row Lock Waits: Includes segments that had a large number of row locks on their data.

          Segments by ITL Waits: Includes segments that had a large contention for Interested Transaction List (ITL). The contention for ITL can be reduced by increasing INITRANS storage parameter of the table

init.ora Parameters: This section shows the original init.ora  parameters for the instance during the snapshot period.